Grafting of Methyl Methacrylate and Styrene onto Polychloroprene Latex for Compatibilization of Polychloroprene Latex/Styrene-Acrylate Emulsion Blends

Grafting of methyl methacrylate (MMA) and styrene (St) onto polychloroprene latex (CRL) was carried out successfully using emulsion polymerization. The chemical structure of the grafted copolymer was characterized using Fourier transform infrared spectroscopy. The compatibilizing effects of the grafted polymer CRL-g-(MMA-co-St) on the CRL/styrene-acrylate emulsion (SAE) blend were investigated using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and mechanical testing. The results showed that the mechanical properties of the contained CRL-g-(MMA-co-St) blend improved significantly in comparison to those of the simple CRL/SAE blend. For the contained CRL-g-(MMA-co-St) blend, the maximum tensile strength (6.72 MPa) and the maximum elongation at break (1142.6%) were obtained when the content of SAE was 60% (occupied by the total dry weight). At the same content of SAE, the T-peel and lap shear strengths of the contact adhesive derived from the contained CRL-g-(MMA-co-St) blend were 5.3 N/mm (canvas to canvas) and 1.8 MPa (plywood to plywood), respectively. The grafted copolymer CRL-g-(MMA-co-St) showed a remarkable compatibilizing effect on the CRL/SAE blends by drastically improving their mechanical properties.